Started stutter at 5 ,now I'm 26 and recovered almost.. Here are my advises.. 1) every time he stutter,you as a parent don't lose eye contact 2) your son will be going through a lot of things in the coming years ,Try working on his nerves , 3) exercises will definitely help at this age ,worked for me in teens too. (I'm a medical doctor ,but part time counsel parents and kids about speech issues) 4) tongue twister helps , new tongue twister everything,play games (try funny phrases ,so that so both laugh on yourself,helps in Bonding too) 5)never tell him ,speak this way or that way ,while he is speaking...do that some other time Wish you best of luck mate...🤝